General heat shielding film products are mostly resin materials added with dye, metal, mica, ATO, LaB6 and the like. However, these heat shielding films have poor shielding performance against infrared light, and poor heat shielding performance. Further, these heat shielding films have poor weather resistance, and they also have the problem of color fading upon prolonged sun exposure. Additionally, for example, the heat shielding products of the multi-layered silver film have excellent heat shielding effects, but have poor stability in the air. Moreover, these products often have high fabrication costs and complex manufacturing process.
Conventional heat shielding products usually do not have both high light transmission and high heat shielding ability. For example, transparent oxide conductive materials such as antimony tin oxide (SnO2:Sb, abbreviated as ATO) and indium tin oxide (SnO2:In, abbreviated as ITO) usually need to be added into heat shielding products. Since the transparent oxide conductive materials have lower conductivity, the plasma wavelength of the transparent oxide conductive materials is greater than 1000 nm (these materials have a plasma wavelength of approximately 1000-2500 nm). Therefore, when these materials are added to the heat shielding film materials, although the visible light transmission rate of the heat shielding film is increased, its infrared rejection is often reduced by 50%. Further, the addition of the aforesaid materials also causes a reduction of heat shielding properties. In addition, although the heat shielding product having resin materials added with metals has 50% infrared rejection, the visible light transmission rate is only 50%. Moreover, the heat shielding film materials as added with tungsten oxide and an alkali metal have increased visible light transmission rate and insufficient infrared rejection. However, when the infrared rejection of these materials is increased, there is still the problem of reduced visible light transmission rate. Further, if LaB6 having a plasma wavelength of 700 to 1100 nm is added to heat shielding film products, the heat shielding film product has better infrared rejection due to LaB6 having higher conductivity, but there is still insufficient visible light transmission rate. Thus, it is clear that conventional heat shielding film products cannot have high transparency as well as high heat shielding effects. As such, there is a need to develop a heat shielding material with high light transmission rate, high heat shielding ability and high stability.